中文摘要：

目的采用Meta分析的方法,探索5,10-亚甲基四氢叶酸还原酶（MTHFR）和神经管畸形（NTDs）之间的关系。方法在中国知网和Pubmed等国内外数据库中,根据检索标准,收集儿童MTHFR C677T多态性与NTDs相关的文献,应用Stata 11.0软件对各文献进行数据分析。结果共9篇文献符合纳入标准。分析后发现,在TT/CC、CT＋TT/CC和TT/CT＋TT遗传模式下,OR值分别为1.78（95%CI1.12,2.81）、1.28（95%CI1.07,1.55）和1.73（95%CI 1.07,2.78）。结论 MTHFRC677T多态性与NTDs之间存在显著关联。儿童MTHFR基因C677T多态性是神经管畸形发病的一个危险因素。

英文摘要：

Objective Methylenetetrahydrofolate reductase （MTHFR） polymorphism C667T has been associated with the neural tube defects（NTDs）,this common missense mutation in the MTHFR gene may reduce enzymatic action, and may be involved in the neural tube defects. The aim of this study was to investigate the relationship of the MTHFR C677T polymorphism with the neural tube defects. Methods Electronic search strategy was carried out among the five databases from home and abroad to collect qualified re- search papers, according to the inclusion and exclusion criteria . Case--control studies on association between MTHFR polymorphism and susceptibility to NTDs were collected. The combined OR values and their 95 %C1 were calculated using STATA 7.0. Results Nine eligible studies were included. Statistics of the combined data showed a significant difference between the children NTDs offspring carrying TT/CC, CT＋ TT/CC and TT/CT＋ TT of MTHFR gene C677T and controls. The pooled OR（95 %CI）were 1.78 （1.12 -2.81）, 1.28（1.07-- 1.55） and 1.73 （1.07-- 2.78） respectively. Conclusion The results suggested that the children＇s MTHFR gene C677T polymorphism were risk factors to NTDs .